1. Field of the Invention
The present invention relates to a semiconductor device constructed such that a semiconductor chip is bonded to a surface of a solid device such as a wiring board or a second semiconductor chip.
2. Description of Related Art
Semiconductor devices of a flip chip bonding structure are hitherto known which, for example, have a semiconductor chip bonded to a surface of a wiring board with its face down. In such a flip chip semiconductor device, the semiconductor chip is bonded to the wiring board with an active surface thereof being opposed to the wiring board. The semiconductor chip is physically and electrically connected to the wiring board in a predetermined spaced relation by a plurality of bumps provided between the semiconductor chip and the wiring board. Solder balls are provided as terminals for external connection on a rear surface of the wiring board. Where the number of the terminals are relatively great, the wiring board has a greater size than the semiconductor chip as viewed in plan. Therefore, a metal stiffener is provided as surrounding the periphery of the semiconductor chip to keep the planarity of the wiring board.
The semiconductor device having the aforesaid construction is fabricated, for example, by first bonding the semiconductor chip onto the wiring board and then providing the stiffener (which is a separate member from the semiconductor chip) on the wiring board. Therefore, the semiconductor chip and the stiffener, if each having a small thickness, are liable to be cracked or chipped during handling thereof for mounting thereof on the wiring board. This poses limitations to thickness reduction of the semiconductor chip and the stiffener and, hence, to thickness reduction of the entire semiconductor device.